Late Quaternary environmental studies on salt lakes in western Rajasthan, India: a summarised view

Climate Change and Monsoon: Looking Into Its Antecedents

“…In support of the inferences arrived at by magnetic parameters for the playas and the Gulf of Kutch one can list the following studies: The salt lakes in western Rajasthan recorded monsoon dynamics between 5 ka and 3.5 ka, saline conditions from 20 ka to 13 ka and freshwater conditions prevailed from 9 ka to 6 ka (Kajale & Deotare, 1997). Hypersaline conditions prevailed at Didwana (Singh et al, 1990) from 20 ka to 13 ka and freshwater from ~9 to 6 ka.…”

Monsoon in history and present

“…The increased intensity of ISM during this interval is linked with the warming of the circum-North Atlantic region (Martín-Puertas et al, 2009), synchronous with intense solar insolation and associated with the northward shift of the ITCZ (Haug et al, 2001;Solanki et al, 2004). In contrast, several studies from the west and south India documented a significant phase of weak monsoon precipitation between ~2000 and 1,500 yr BP (Wasson et al, 1984;Singh et al, 1990;Kajale & Deotare, 1997;Deotare et al, 1998;Enzel et al, 1999;Jain & Tandon, 2003;Jain et al, 2004;Limaye et al, 2014) (Fig. 2N).…”

“…Several excavations, investigations and the discovery of over a thousand sites in all parts of the Indian subcontinent except the west coast, including Kerala, have drawn attention to the dispersion of monsoon-based farming and corresponding settled village life beyond the domain of the Fig. 2-A Wasson et al, 1984;Kajale & Deotare, 1997;Deotare et al, 1998;Enzel et al, 1999;Sinha et al, 2007); (O) the geochemical (C/N ratio) record from Kukkal Lake, Tamil Nadu (after Rajmanickam et al, 2017); (P) the δ 13 C record from Nilgiri Peat, south India (after Sukumar et al, 1993).…”

“…The evidence of weak monsoon is documented from NW India at ~3500 yr BP, followed by the strengthening of ISM after ~3500 yr BP and a short pulse of dry climatic between ~3238 and ~2709 yr BP (Prasad et al, 2007. Several lakes in the Thar like the Bap-Malar, Didwana, Lunkaransar also showed high salinity levels or dried up between ~3500 and 1500 yr BP (Wasson et al, 1984;Singh et al, 1990;Kajale & Deotare, 1997;Deotare et al, 1998;Enzel et al, 1999) (Fig. 2N).…”

Multi-proxy evidence for an arid shift in the climate and vegetation of the Banni grasslands of western India during the mid- to late-Holocene

“…The herbaceous/shrub pollen spectra from the Banni region were classified as (1) mesic taxa such as Cyperaceae and Malvaceae that require more moisture for their survival (Duffin, 2008; Gil-Romera et al, 2006; Miller and Gosling, 2014), (2) arid taxa such as Asteraceae, Caryophyllaceae and Euphorbiaceae that require less moisture for their survival (Gil-Romera et al, 2006; Horn et al, 2014; Scott, 1999; Shmida, 1985), (3) taxa that grow in arid and saline conditions such as Chenopodiaceae-Amaranthaceae (Cheno-Ams) (Gil-Romera et al, 2006; Malamud-Roam and Lynn Ingram, 2004; May, 1999; Scott, 1999; Shmida, 1985) and (4) desert taxa such as Ephedra species that grow under arid desert conditions (Kajale and Deotare, 1997; Singh et al, 1974). Arboreal pollen grains included legumes, non-legumes and temperate pines that are wind dispersed.…”